Aspects of membrane function and assembly will be studied in Staphylococcus aureus and Spirillum itersonii. The inducible nitrate reductase and alpha-glycerophosphate dehydrogenase in Staphylococcus will be purified and the effect of heme determined on the integration of these enzymes into functional membrane complexes. Heme synthesis is to be studied in the Spirillum membrane with the aim of establishing the mechanism of reduction of ferric-iron by the respiratory chain.